Update on Alternative Design of jleic ion injector Complex B Update on Alternative Design of jleic ion injector Complex B. Mustapha & J. Martinez Physics Division, ANL Collaborators: V. Morozov, F. Lin, Ya. Derbenev & Y. Zhang JLEIC Collaboration Meeting April 1-3, 2019, JLab, Newport News, Virginia

Outline Main Motivations of Alternative Design Studies Review: Alternative for the 65 GeV Design New Goals for the 100 GeV Design Options for the E-ring as Large Booster Options for the Pre-Booster Ring Summary & Future work B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Main Motivations for the Alternative Ion Injector Design The idea is not to replace the baseline design but rather to investigate alternative options for the different components of the ion complex that have the potential of lowering the cost, mitigating the risk, and be ready for possible staging and future upgrades of the project Reduce footprint and cost of the Ion Complex Compact Injector Linac (130 MeV instead of 280 MeV protons) Small Pre-booster Ring (5-8 GeV, no figure-8) Consolidate Electron Ring as Large Ion Booster Lower the risk Use RT magnets whenever possible Avoid transition crossing for all ions Staging / Upgrade Ion Injector Complex Compatible with 65, 100 and 140 GeV CM Only Upgrade Ion Collider Ring B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Review for the 65-GeV Design

Review: Alternative for the 65 GeV Design More Compact Lower-energy Linac 3 GeV pre-Booster: Spin polarization preserved by S. Snakes E-Ring as Large Booster with ~ 12 GeV is beneficial for a 200 GeV collider upgrade Separate RF and spin correction sections for electrons and ions? The E-Ring and Ion Collider Ring are stacked vertically in one tunnel Ion injection from the E-Ring to Ion Ring is a vertical bend B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

A More Compact Lower-Energy Linac Original New  Item / Parameter Original New Comments Protons (MeV) 280 130 Lower output W Pb (MeV/u) 100 42 SC modules 16 5 ~ 1/3 Cost Total Length 55 ~ 1/2 Tunnel cost Total Power (kW) 560 260 ~ 1/2 The new design is ~ 1/3 the construction cost of the original B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

A More Compact Pre-Booster Ring Original 3-GeV Pre-Booster New Design Design Parameters The new design is ~ 1/2 the construction cost of the original Beam Optics B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

E-Ring As Large Booster for the Ions – Added RF Sections for Ions … Electrons Only Electrons & Protons e- Collision Optics at 5 GeV Proton optics at 3 GeV, Injection from Booster i & e RF i & e RF Ion RF sections were inserted in the straight sections, across from electron RF Proton beam optics studied at the injection energy of 3 GeV B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Spin Dynamics in 3-GeV Pre-Booster Intrinsic resonances (proton) Imperfection resonances (proton) Intrinsic : COSY vs. Zgoubi Good overall agreement between COSY and Zgoubi No resonances observed for deuterons, first one expected at ~ 5.6 GeV/u Possible spin correction schemes for protons are listed in table below B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Beam Formation in Alternative 65-GeV Design Proton beam parameters in the Rings Lead beam parameters in the rings The main issue is the high SC tune shift for Pb ions in the E-ring / Large Booster A 5-GeV or higher booster energy will reduce it to below 0.15 B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Progress Reported in Conference Proceedings … “An Alternative Approach for the JLEIC Ion Accelerator Complex”, B. Mustapha, P. Ostroumov, A. Plastun, Z. Conway, V. Morozov, Y. Derbenev, F. Lin and Y. Zhang, Proceedings of NAPAC-2016, October 9-14, 2016, Chicago, IL. “A More Compact Design for the JLEIC Ion Pre-Booster Ring”, B. Mustapha, P.N. Ostroumov and B. Erdelyi, Proceedings of NAPAC-2016, October 9-14, 2016, Chicago, Illinois. “Adapting the JLEIC Electron Ring for Ion Acceleration”, B. Mustapha, J. Martinez Marin, Z. Conway, P. Ostroumov, F. Lin, V. Morozov, Y. Derbenev and Y. Zhang, Proceedings of IPAC-2017, May 14-19, 2017, Copenhagen, Denmark. “Beam Formation in the Alternative JLEIC Ion Complex”, B. Mustapha et al, Proceedings of IPAC-18, April 29 – May 4, 2018, Vancouver, Canada “Spin Dynamics in the JLEIC Alternative Pre-booster Ring”, J. Martinez and B. Mustapha, Proceedings of IPAC-18, April 29 – May 4, 2018, Vancouver, Canada B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Main Conclusions for the 65-GeV Design … Lower linac energy seems reasonable for both proton and heavy-ion injection into a small pre-booster ring Higher energy pre-booster of 5 GeV or higher is required to lower SC tune shift for heavy ions in the e-ring E-ring as Large Ion Booster seems feasible from beam optics point of view Changes adopted to the baseline design Lower-energy shorter linac  150 MeV Two boosters: 8 and 12 GeV RT magnets in the boosters, SC only in collider ring B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

New Goals for the 100-GeV Design More Compact Lower-energy Linac ~ 5 GeV pre-Booster: Spin polarization preserved by S. Snakes E-Ring as Large Booster with ~ 16 GeV is beneficial for 200 GeV collider & future upgrade If practical limitations, Large Booster can be separate, in same tunnel 6 The E-Ring and Ion Collider Ring are stacked vertically in one tunnel Ion injection from the E-Ring to Ion Ring is a vertical bend B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Design Options for E-Ring / Large Booster

Limitation of Current E-ring as Large Booster 3 Options considered (NAPAC-2016 Paper) Parameter Baseline (PEP-II magnets) Low-ɛ (New RT magnets) TME design (RT dipoles, SC quads) Cell length (m) 15.2 11.4 Transition γ 23 32 Proton (GeV) 11 15 37.5 Pb (GeV/u) 4.4 6 Dipole (T) 0.36 0.5 1.3 Quad (T/m) 25 66 Limitation Dipoles Quads - In current e-ring lattice, SC quads are required to reach ~ 16 GeV/u for Pb For a room-temperature ring, a new design of e-ring/ion booster is needed Design it for 16 GeV/u ions then optimize it for storing electrons Possible options: combined function dipoles, long quads, quad doublets … B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Combined Function Magnet Options Tapered Dipole Face Offset Quadrupole High Field, Low gradient High Field, High Gradient The offset quadrupole option is not practical and more expensive, because all dipoles will need to be quadrupoles … Despite the low gradient, the tapered dipole face solution may provide the additional focusing required An electron storage was recently proposed with tapered dipoles with up to 14 T/m! C. Bailey et al, “Magnet Design for DIAMOND DDBA Lattice Upgrade”, IPAC-2014 B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Large Booster Solution with Tapered Dipoles All RT Figure-8 Design 16 GeV/u Lead beam optics Parameter Value Circumference, m 2256.6 Maximum βx, m 85 Maximum βy, m 73 Maximum dispersion, m 1.05 γ 18.17 Transition γ 18.6 Quad. half aperture, cm 5 Quad. max. grad. T/m 20 Quad. length in arc, m 1 Dipole max. field, T 1.3 Dipole gradient, T/m 4 Dipole Length, m 6 Cell Length, m 16.4 12 GeV Electron beam optics B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Issues / Limitations of Tapered Dipoles Preliminary tapered magnet design: Gap = 5 cm, Gradient ~ 3 T/m Needs further optimization Dipole with Tapered Pole Face The gradient component reduces the bending field: Bmax=B0+G*dy ~ 1.6 T  this directly affect the minimum bend radius allowed The Maximum gradient depends on the gap and width of good field region  so far assuming 5 cm gap (~7*sigma) and +/- 5 cm good field region The dipole needs to be curved to preserve the same focusing relative to central orbit. B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Large Booster Solution with Quad Doublets All RT Figure-8 Design 16 GeV/u Lead beam optics Parameter Value Circumference, m 2251.6 Maximum βx, m 85 Maximum βy, m 73 Maximum dispersion, m 1.16 γ 18.17 Transition γ 18.7 Quad. half aperture, cm 5 Quad. max. grad. T/m 20 Quad. length in arc, m 0.69 Dipole max. field, T 1.6 Dipole Length, m 5.4 Cell Length, m 17.3 12 GeV Electron beam optics B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Large Booster Solution with Long Quads All RT Figure-8 Design 16 GeV/u Lead single-cell optics Parameter Value Circumference, m 2220.4 Maximum βx, m 85 Maximum βy, m 73 Maximum dispersion, m 1.15 γ 18.17 Transition γ 18.3 Quad. half aperture, cm 5 Quad. max. grad. T/m 20 Quad. length in arc, m 1.35 Dipole max. field, T 1.6 Dipole Length, m 5.4 Cell Length, m 17.1 B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Design Options for Pre-Booster

Pre-Booster Energy vs. Beam Size in Large Booster Parameter 5-GeV Pre-B Proton Pb67+ 6-GeV Pre-B proton 6-GeV Pre-B Pb67+ 8-GeV Pre-B 8-GeV Pre-B Pb67+ Inj. Energy (GeV/u) 5 1.2 6 1.5 8 2 βγ value 6.2493 2.0582 7.3266 2.4111 9,4734 2.9840 RMS norm. ε (π.mm.mrad) 3 RMS un-norm. 0.480 1.458 0.409 1.244 0.317 1.005 Vertical βmax, m 90 βmax in dipole, m 30 σ in dipole (mm) 3.8 6.6 3.5 6.1 3.1 5.5 7σ Aperture (mm) 26.6 46.3 24.5 42.7 21.7 38.5 5-GeV Pre-booster will require 6 cm gap for Large Booster dipoles 6-GeV Pre-booster will require 5 cm gap for Large Booster dipoles (thin-wall VC) 8 GeV Pre-booster will require 5 cm gap for Large Booster dipoles (regular 5 mm wall VC) B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

6-GeV Pre-Booster Design Option All RT Race-Track Design 6 GeV proton beam optics Parameter Value Circumference, m 256.1 Maximum βx, m 10.6 Maximum βy, m 11.14 Maximum dispersion, m 1.04 Tune in X 9.45 Tune in Y 9.36 Extraction γ 7.39 Transition γ 7.91 Quad. half aperture, cm 5 Quad. max. grad. T/m 20 Quad. length in arc, m 0.56 Dipole max. field, T 1.6 Dipole Length, m 1.51 Siberian snake for p, 3He No resonances for d B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

8-GeV Pre-Booster Design Option All RT Race-Track Design 8 GeV proton beam optics Parameter Value Circumference, m 319.3 Maximum βx, m 10.78 Maximum βy, m 10.99 Maximum dispersion, m 0.83 Tune in X 11.47 Tune in Y 11.41 Extraction γ 9.53 Transition γ 9.78 Quad. half aperture, cm 5 Quad. max. grad. T/m 20 Quad. length in arc, m 0.66 Dipole max. field, T 1.6 Dipole Length, m 1.62 Siberian snake for p, 3He No resonances for d B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Summary & Future Work … The Pre-Booster can be small RT race-track ~ 6 GeV - 250 m circumference, solves heavy-ions SC effects but will require Siberian snake for proton and 3He The Large Booster can be up to 16 GeV for all ions (16 GeV/u) in the same footprint as the E-Ring with all RT magnets, the high energy is beneficial for 100-GeV CM and upgrade to 140-GeV The new Large Booster design can be used as E-ring, beam optics seems feasible, but can be separate in case of practical or operational limitations Next: Optimization of a selected option – 6 GeV race-track Pre- Booster with 16 GeV/u Large Booster with quad doublets focusing B. Mustapha Alternative JLEIC Ion Injector Complex JLEIC Spring Meeting, JLab, April 1-3, 2019

Thank you!